MEDFORD — Gang activity appears to be increasing in Southern Oregon.

Medford police Lt. Tim Doney said about 100 people with some affiliation to gangs have been identified so far, up from 55 last spring.

Although the list includes white supremacists, motorcycle gangs and a few Crips, Doney said the surge in growth has come with Hispanic street gangs.

He said the most active are the Nortenos and Surenos, which have roots in the California prison system, and subsets of those two gangs.

Doney described gang activity in the Rogue Valley since the early 1990s as “like the tide,” ebbing and surging over time.

Recently, police have been keeping a close watch on a group of young men involved in a fatal fight in September at an apartment complex and are now being released from jail.

Although prosecutors have said all the direct participants in the fight that led to the stabbing death of 24-year-old Marco Diaz face serious consequences, other young men who were present or who returned the next day are back on the street after serving jail time for various convictions.

Doney said representatives from the Medford and Central Point police departments, the Jackson County Sheriff’s Department, the Commission on Children and Families and the District Attorney’s Office have met to discuss and coordinate enforcement efforts.

Gang activity and ways to prevent it are common topics at monthly meetings between Medford police and school officials.

“We’re currently working with schools, nonprofits and local churches to address some of the issues related to the explosive growth of gangs in recent months since the stabbing,” he said.

Although gangs are a problem, Doney pointed out they still are only a small part of the 87,000 service calls that Medford police respond to annually.